# File lib/diff/lcs/change.rb, line 111
  def initialize(*args)
    @action, @old_position, @old_element, @new_position, @new_element = *args

    unless Diff::LCS::Change.valid_action?(@action)
      raise "Invalid Change Action '#{@action}'"
    end
    unless @old_position.nil? or @old_position.kind_of? Fixnum
      raise "Invalid (Old) Position Type"
    end
    unless @new_position.nil? or @new_position.kind_of? Fixnum
      raise "Invalid (New) Position Type"
    end
  end